I have a report that export to excel it takes about an hour to get the data and about 30 min to render it creates an Excel spreadsheet 90 Meg...

I believe that what you needed:

select

 a.CardAccount,

 b.CardNumber,

 MarchCount = (select count(*) from TableC c (nolock)

   where c.TransactionDate between '03/01/2006' and '03/31/2006 23:59:59.999'

   and c.CardNumber = b.CardNumber),

 AprilCount,

...

....

 DecemberCount

from TableA a (nolock)

inner join TableB b...